1. The Field of the Invention
This application is directed to methods and devices for delivering multi-part compositions. More particularly, the application is directed to syringes and delivery tips for delivering multi-part medical and dental compositions.
2. Relevant Technology
Many modern formulations are packaged in two parts, often known as xe2x80x9cA/B componentsxe2x80x9d or xe2x80x9cfirst and second materialsxe2x80x9d. Upon mixing, these A/B components typically undergo a chemical reaction which causes the resultant composition to xe2x80x9cset upxe2x80x9d in some desired manner, for example, by forming a hardened material. In the dental field, for example, several two-part formulations currently enjoy wide use, such as glass ionomer cements and resinous luting cements. Dental impression materials are also typically made using A/B components.
In order to function properly, it is important that the A/B components of these two component systems be separated until it is desired to mix the components. Typical techniques for retaining A/B type materials in a separated state before mixing the materials include loading the A/B materials into two-part material delivery apparatuses having separate side-by-side barrels or tubes. The side-by-side barrels are each configured to receive a separate material therein and deliver the separate material therefrom
Examples of such two-part material delivery apparatuses having side-by-side barrels are disclosed in U.S. Pat. Nos. 5,290,259; 5,328,462; 5,643,206; 5,665,066; and 5,697,903, assigned to Ultradent Products, Inc., each of which is incorporated by reference herein. A wide variety of such two-part material delivery apparatuses exist. Such apparatuses typically have a proximal material receiving end, and a distal delivery end. The distal delivery end typically features first and second openings which are adjacent one another and which are located at the end of neighboring barrels. Material delivered from one of the adjacent openings is typically delivered next to and in parallel relationship with the material delivered from the other opening.
Upon delivery of the first and second materials through the adjacent openings, the practitioner can then mix the materials in a mixing bowl, syringe, mixer or other device. Although mixing of the A/B materials is the ultimate goal of A/B type delivery systems, premature mixing and hardening of material is generally detrimental. Nevertheless, in typical A/B type delivery systems, it is common for a certain amount of undesired commingling of A/B type materials to occur as the A/B materials exit the adjacent first and second openings. Sometimes, some of the mixed material contacts the distal delivery end of the delivery system, such as by depositing on one of the edges of the proximal and distal openings. Such mixed material tends to harden on the delivery system.
If mixed material hardens in an opening, the hardened material can block or impede the flow path of a barrel. The disruption of the normal flow pattern can cause additional mixing and hardening in undesired areas. Thus, the buildup of reactive A/B materials on the distal end of a delivery system can slow, stop, or otherwise disrupt the delivery of the materials through the system.
The problem of material build up becomes particularly acute when a delivery system is used, then temporarily set aside or stored before a subsequent use. This allows time for mixed materials to harden before the subsequent use.
Another problem associated with the delivery of A/B materials is that uncovered delivery ends can dry out or become inadvertently contaminated. While it is possible to cover delivery ends with a cap, such caps can become readily separated from the delivery system and lost. Furthermore, it can be difficult to achieve a reliable seal between a delivery tip and a two-part material delivery apparatus which delivers material to the delivery tip, thereby allowing seepage of material at the junction between the tip and the two-part material delivery apparatus.
There is, therefore, a need in the art for a system for delivering A and B type materials which keeps the materials separate until mixing is desired and thereby avoids cross-contamination and hardening of the materials until the desired time. Specifically, there is a need in the art for a system which avoids cross-contamination between two materials at a distal delivery end of the system.
There is also a need in the art for an improved seals within the material delivery systems to prevent co-mingling of the A/B materials as the materials are delivered for mixing or during storage. Furthermore, there is a need in the art for an improved system for covering the delivery end of the system during storage.
It is therefore an object of the invention to provide an improved delivery system for delivery of A/B type materials.
It is another object of the invention to provide an improved system for delivering A and B type materials which keeps the materials separate until mixing is desired and thereby avoids cross-contamination and hardening of the materials until the desired time. Specifically, it is an object of the invention to provide a system which avoids cross-contamination between two materials at a distal delivery end of the system
It is another object of the invention to provide an improved seals within the material delivery systems to prevent co-mingling of the A/B materials as the materials are delivered for mixing or during storage.
It is another object of the invention to provide an improved cap for covering the delivery end of the system when not in use.
These objects are achieved through an inventive syringe system for mixing first and second materials together and delivering the mixed materials. The syringe system has a dual barrel cartridge with a uniquely configured dual lumen nipple that is removably coupled with a uniquely configured tip. When the tip is positioned on the dual lumen nipple of the dual barrel cartridge, two separate flow paths are created so that the A/B materials remain separated until being brought together for mixing in the tip.
The dual barrel cartridge has a proximal grasping end opposite from a distal delivery end. The dual barrel cartridge has two barrels that each having an opening at the proximal grasping end of the dual barrel cartridge and a barrel outlet at the distal delivery end of the dual barrel caridge. A plunger unit with two plungers is inserted into the two barrels of the dual barrel cartridge.
The dual barrel cartridge has opposing claws at its distal delivery end which engage a removable collar. The removable collar holds the tip on the nipple once the tip has been
inserted though an aperture of the removable collar and the collar locked under the claws of the dual barrel cartridge.
The dual lumen nipple has a receiving end opposite from a terminal end. The dual lumen nipple has cylindrical sidewalls that extend integrally from the distal delivery end of the dual barrel cartridge. The lumens are preferably divided by a septum that extends integrally from the distal delivery end of the dual barrel cartridge and across the sidewalls. Each lumen is in fluid communication with one of the barrels of dual barrel cartridge through the barrel outlets. The sidewalls of the nipple are partially terminated such that each lumen has a side portal.
As the plungers are depressed into the barrels, the first and second materials are respectively pushed through the barrel outlets and into lumens of the dual lumen nipple. The materials are then pushed out of the lumens via the side portals of the lumens. Each side portal has a top defined by a flat sealing head that extends at the terminal end of the dual lumen nipple from the septum and a portion of the sidewalls. The flat sealing head preferably has truncated flanges that extend perpendicularly relative to the septum Each truncated flange has a length that permits the material delivered out of each side portal to pass around the truncated flange when the nipple is inserted into the delivery chamber of the tip.
The delivery tip has a proximal coupling end opposite from a distal delivery end. The delivery tip has a hub at its proximal coupling end that is integrally connected to a mixing element housing. The mixing element housing has a mixer chamber in which a static mixing element is housed. The tip is preferably designed to enable the materials to separately enter the static mixing element.
The hub of the delivery tip has hub sidewalls and a hub shoulder extending inward from the hub sidewalls to the mixing element housing. The hub also has a delivery chamber that is sized to receive the nipple in a releasable manner. The delivery chamber has a delivery chamber opening that is opposite from a mixing chamber inlet. The mixing chamber inlet is the opening into the mixing chamber and enables the delivery chamber to be in fluid communication with the mixing chamber.
The hub sidewalls have interior surfaces that include opposing raised sidewall portions between opposing sidewall channels. Similarly, the hub shoulder has interior surfaces that include opposing raised shoulder portions between opposing shoulder funnels. The opposing raised sidewall portions and the opposing raised shoulder portions are aligned and adapted to form a seal with the sidewalls and the flat sealing head of the nipple once the nipple is inserted into the delivery chamber. The opposing sidewall channels are aligned with the opposing shoulder funnels such that there is a separate pathway for each material from each side portal to the mixing chamber inlet.
Upon reaching the mixing chamber inlet, the materials are preferably still separate from each other. The mixing element is preferably positioned with its first vane in the mixing chamber inlet. The first vane has a leading edge that is positioned such that the leading edge extends between the opposing raised shoulder portions of the hub shoulder, is centered on the opposing raised shoulder portions and is flush with the opposing raised shoulder portions while extending slightly beyond the opposing shoulder funnels. This configuration enables the leading edge to be tightly pressed up against the flat sealing head. The leading edge of the first vane may even be pressed firmly enough to form a seal with the flat sealing head. After the materials pass through the first vane without contact each other, then they enter the second vane which is oriented such that the materials contact each other and the mixing process begins. After passing through the series of vanes of the mixing element, then the two materials are fully mixed together and exit as a mixed material from the mixing element housing.
The system also includes a cap for insertion over the nipple after the delivery tip has been removed. Like the tip, the cap has surfaces that engage the side portals and surfaces that form a seal with the sidewalls and the flat sealing head of the nipple once the nipple is inserted into the nipple chamber of the cap. This enables the materials held in the barrels to be sealed for later use.
As indicated above, one of the advantages achieved through these features is that materials separately exit the dual lumen nipple of the double barrel cartridge and continue to be maintained in separate pathways even after being delivered into the nipple. More particularly, the pathways remain distinct until after the materials enter the mixing element. This eliminates the potential for cross-contamination and hardening of the materials before use of the materials is desired.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.